Mitral valve surgeries: repair or replace
Starting from the early 1950s, open heart surgery has become the golden standard for mitral valve repair or replacement. The mitral valve is replaced with either a prosthetic mechanical valve (ball valves) or a bio-prosthetic tissue valve (pig, horse, cow) which the surgeon sutures into place by hand.
However, open heart surgery can be very invasive (it requires a 6-8 in incision down the center of the chest), and requires the use of a heart-and-lung machine (a machine that takes over the heart's function, the patient's heart is stopped and all of the blood is re-routed). Thus the patient may need longer recovery times and may suffer from unwanted complications. A new type of surgery, called "minimally invasive" surgery is emerging.
Minimally invasive surgery entails a 3-4 in chest incision, and using heart-and-lung machine, but for our case we will not use it. Therefore the blood is still flowing naturally though the heart. Opening up the heart without massive blood leakage, and suturing a new prosthetic valve becomes a challenge.
To get access to the mitral valve, a cut is made in the left atrium appendage (LAA), which is a small sac in the heart that can first be clamped at one end. The blood is drained from the LAA and a special device called the universal cardiac introducer (UCI) is sutured to where the cut was made. The UCI already contains the tools necessary to perform mitral valve surgery, it also has leak-proof ports to allow for the manipulation of these tools. The clamping of the LAA is removed, and blood resumes normal flow. The tools contained within the UCI are then used to perform the mitral valve surgery.
Effectively, the UCI is a "sealing tool" that gives us the ability to use different tools to perform the surgery on a beating heart without massive blood loss. The surgeon can now theoretically suture the new prosthetic valve into place, however, this suturing will take considerable time and effort.
Therefore a new intracardiac, fast deploying, suture-less, and self-anchoring tool is needed to deploy the prosthetic valve into position. It must withstand the heart's working pressures, must not interfere with blood flow, must be used together with the UCI during a beating heart mitral valve replacement surgery. It must also be reversible, in case the surgery encounters complications.